Frequently Asked Questions

Have a question? Need information? Scroll to see the answers for our most FAQs.

You will find information on our retail products as well as our custom antibody services and protocols to use with whatever you order! If you can not find the answer to your specific question, please contact technical support at techsupport@prosci-inc.com or give us a call. We are always happy to help.

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General

Do you have recommended protocols for your products?

Yes, please select a protocol from our protocol section below to learn more. Any standard protocol is also acceptable.

What are the storage conditions?

Because of the diversity of products we currently offer, this is no longer a simple answer. Please look at the product's data sheet and/or the product label for pertinent information.

Can I purchase cell lines from your company?

We only sell products (i.e. slides and lysates) made from cell lines, not the actual cell lines themselves.

Antibodies

Have all of your antibodies been tested for use with IHC and other staining methods?

We are still in the process of characterizing our antibodies for this application. If a particular antibody has been tested for IHC, there will be an image on the data sheet.

I can not find the peptide sequence used for the antigen.

Most antigen information is proprietary and not available for the general public. If you have questions about predicted cross-reactivity, please send the target sequence to techsupport@prosci-inc.com and we will perform an alignment for you.

Are the Western Blot images on your data sheets under reducing or non-reducing conditions?

For our western blots we use reducing agents, however, either method can be used.

A standard two rabbit schedule uses 1mg of antigen (peptide, protein, etc.), but please provide 1.5-2mgs of protein are recommended, especially if you require ELISA or extensions. For affinity purification, 2-3mg of lyophilized peptide and 3-5mg of soluble protein are required. We prefer a concentration of 1mg/mL or greater. Check out our Antigen Requirements page to learn more.

What if I don't have enough peptide or protein?

This is not a problem, just send us what you have ready and we will start your project. You can send us more when it becomes available.

How pure does my antigen need to be?

In the most general terms, peptide antigens need to be around 70% purity or greater and protein antigens need to be at least 90% purity or greater. The high purity requirement comes from 2 main points:

Protein antigens should be of a higher purity because the manufacturing process can yield other unrelated proteins which will cause different immune responses. With synthetic peptide antigens, the impurities tend to be fragments of partially synthesized peptides vs. something completely unrelated to the desired target. Partially synthesized peptide antigens may still be sufficient for generating the desired immune response.

The purer the antigen, the more precise the host’s immune response will be. Any impurities in your antigen run the risk of being immunoreactive as well, generating undesirable antibodies that could cause high background.

The necessary antigen purity also depends upon what you are trying to do with your project. For polyclonal antibodies, >70% peptide antigen purity is fine, but for monoclonal antibodies, >90% antigen purity is the standard. Additionally, peptide antigens containing modified amino acids should also be >90% purity even for polyclonal antibody development.

Though these are reasons to try and provide very pure antigens for the best results, this does not mean we will not accept lower purity antigen. A custom project is just that: custom. We will still generate an antibody for you if you provide us with 60% pure protein, but you may not obtain the desired antibodies at the end. With antibody development and production, what you put in is what you get out.

Can I send you a gel strip?

Sure, however gel strips can only be accepted for our package I. Gel strips can not be used in conjunction with ELISA and affinity purification. Additionally, the protein should be reasonably concentrated prior to running on the gel (2-5 mg/ml). Just stain the whole strip with coomassie blue. Then de-stain, rinse, and cut the desired strip from the gel (Please don't "chop it up"). After you cut the band from the gel, place it in a 15 or 50ml conical tube with an icepack- don't freeze it.

How do I de-stain my gel strip?

Use 5% methanol, 7.5% acetic acid, and fill the remainder with ddH2O. De-stain gel in 100mL solution overnight and replace with fresh de-stain if needed. The gel will remain blue even though the coomassie dissociates from the proteins.

What types of antigens do you accept?

DNA plasmid: ProSci can use a DNA plasmid to generate antibodies; however you need to provide an immunization protocol (bleed/boost schedule and quantity of plasmid to be immunized, etc.) because different plasmids require different schedules. Immunizing with a DNA plasmid is different from immunizing with a protein or peptide antigen. The plasmid can be shipped to us on blue ice.

Enzymes: enzymes can easily be used for antibody production; we need to know concentration in order to administer immunizations and to perform ELISAs.

Polysaccharide: at this time we do not accept polysaccharide samples for immunization; they are difficult to get to elicit immune response and we can make no guarantees.

Cells: cells (i.e.: isolated from an organ like the spleen) can be used as an antigen, but we cannot perform an ELISA to determine titer. Blood cells must be washed away before we can accept the immunogen cells.

Cell Lines/Lysates: cell lines and lysates can be used as polyclonal antigen; however they can not be used for a monoclonal antigen as screening via ELISA is not available from ProSci at this time. A lysate would work as an immunogen, but it would contain so many different proteins that the antibody wouldn't be very specific.

Note: We can not use any living organisms for immunization. If the recombinant organisms are dead, and contain no toxic materials harmful to the animals or personnel, they could be used as an immunogen.

If you can not find the type of antigen you would use in this list, please contact Custom Antibody Services at abservices@prosci-inc.com for more information.

Do you offer immunogenic peptide sequence analysis?

Yes, and its FREE. Our scientists will help you select a sequence that has potential to raise a good antibody response. Just email your full length protein sequence(s) along with any supplemental information to abservices@prosci-inc.com and we will have a response in 1 to 2 working days.

What kind of guarantee do you offer for your custom antibody production and services?

This is a great reason for taking advantage of our free antigen design assistance for rabbit polyclonals. If you choose one of the sequences we recommend for peptide synthesis, we will guarantee an immune response to the antigen by ELISA titration in at least one of the rabbits.

What is immunoaffinity purification?

The peptide/protein is bound covalently to CNBr activated Sepharose 4B or SL gel in a column. The antibodies within the polyclonal pool that are specific to this antigen are allowed to bind. The unbound antibodies and other serum proteins pass through the column, and the antigen bound antibodies are eluted. The resulting purified antibody is highly specific. ProSci will provide you with the serum, flow through, purified antibody (a yield from 0.1 mg to 0.5 mg per ml of serum), re-usable column to the antigen of interest and ELISA results.

Do you offer discounts for a large number of projects?

We do offer discounts and custom schedules for high volume and scalable projects. If your company requires large scale antibody projects, please contact our Custom Antibody Services department at abservices@prosci-inc.com or call 1-888-513-9525 x 200.

Do I need to ship my antigen on dry ice? How are you currently storing your protein?

You only need dry ice if the storage conditions are -80°C. If the protein is stable, ice packs are fine. Please ship it standard overnight via FedEx or a similar carrier.

What do I need to send with my antigen?

Please include an order form within your package (preferably in a zip-lock bag) as well as the concentration of the antigen and the buffer used.

Do I have to cleave the tag from my recombinant protein before sending it to you?

Please cleave the larger tags (GST, MBP, etc.) as they can interfere in specific antibody production. Small tags such as His, Myc, and FLAG do not need to be cleaved prior to antibody production.

What is the smallest antigen that will produce an immune response?

Approximately 10-12kDa is necessary for an immune response. Anything smaller needs to be coupled with a carrier protein, typically KLH, so that the immune system can recognize it.

When will I be billed for a custom project?

Invoices are generated the week that animals are immunized, after peptide synthesis.